1. Introduction
The Nobsound VU3 is a versatile audio device that combines the functionality of a dual analog VU meter with a 2-way amplifier/speaker audio switcher. It allows users to dynamically monitor audio signals with its large VU meters and conveniently switch between two amplifiers and two pairs of speakers without repeatedly plugging and unplugging cables. This manual provides detailed instructions for setting up, operating, and maintaining your VU3 unit.
2. Safety Information
- Ensure the device is powered by a stable DC 5V (above 1A) power supply via the Type-C interface.
- Do not connect the VU3 to amplifiers with an actual output power greater than 300W per channel, as this may damage the VU meter.
- Avoid exposing the device to moisture, rain, or extreme temperatures.
- Do not disassemble the unit. Refer all servicing to qualified personnel.
- Keep out of reach of children.
3. Package Contents
Please check the package for the following items:
- 1x VU3 VU Meter & Audio Switcher
- 1x Remote Control (CR2025 3V battery not included)
- 1x USB Cable (for power)
- 1x User Manual
4. Product Overview
4.1 Front Panel
- VU Meters: Dual 60*35mm analog meters displaying audio signal levels.
- IR: Infrared receiver for the remote control.
- Amplifier Indicators (A/B): LEDs indicating the currently selected amplifier.
- Speaker Indicators (1/2): LEDs indicating the currently selected speaker pair.
- Amplifier Selection Button: Toggles between Amplifier A and Amplifier B.
- Speaker Selection Button: Toggles between Speaker 1 and Speaker 2.
- Swing-Range Adjustment Knob: Adjusts the sensitivity and swing range of the VU meter pointers.
4.2 Rear Panel
- Amplifier A/B Inputs: Banana female jacks for connecting two different amplifiers.
- Speaker 1/2 Outputs: Banana female jacks for connecting two different pairs of speakers.
- POWER IN (5VDC 1A Type-C): USB Type-C port for power input.
5. Setup Instructions
5.1 Power Connection
Connect the provided USB cable to the POWER IN (5VDC 1A Type-C) port on the rear panel of the VU3. Connect the other end of the USB cable to a DC 5V (minimum 1A) power adapter (not included) or a suitable USB power source. The unit will power on automatically.
5.2 Audio Connections
The VU3 uses banana female jacks for all audio input and output connections. Ensure all connections are secure and observe correct polarity (+ to + and - to -).
- Connect Amplifiers: Connect your first amplifier's speaker outputs to the AMPLIFIER A jacks on the VU3's rear panel. Connect your second amplifier's speaker outputs to the AMPLIFIER B jacks.
- Connect Speakers: Connect your first pair of speakers to the SPEAKER 1 jacks on the VU3's rear panel. Connect your second pair of speakers to the SPEAKER 2 jacks.
Important: Ensure that the total power output of your amplifiers does not exceed 300W per channel when connected to the VU3.
6. Operating Instructions
6.1 Basic Operation
Once powered on and connected, the VU3 is ready for use.
- Amplifier Selection: Press the 'AMPLIFIER' button on the front panel or the corresponding button on the remote control to switch between Amplifier A and Amplifier B. The respective LED indicator will light up.
- Speaker Selection: Press the 'SPEAKER' button on the front panel or the corresponding button on the remote control to switch between Speaker 1 and Speaker 2. The respective LED indicator will light up.
6.2 VU Meter Functionality
The dual VU meters dynamically display the audio signal levels. They feature a peak LED display to indicate transient peaks in the audio.
- Swing-Range Adjustment: Use the 'SWING-RANGE' knob on the front panel to adjust the sensitivity of the VU meter pointers. Turn it to 'MIN' for less movement (suitable for high-output signals) or 'MAX' for more movement (suitable for low-output signals).
- Backlight Adjustment: The VU meters have a 4-level backlight adjustment. This can typically be controlled via the remote control. The backlight can also be turned off completely.
6.3 Remote Control
The remote control provides convenient access to the VU3's functions from a distance.
- Battery: Insert a CR2025 3V battery (not included) into the remote control.
- Functions: The remote allows you to select amplifiers (A/B), speakers (1/2), and adjust the VU meter backlight brightness.
6.4 Power Off Behavior
When the VU3 is powered off, Amplifier B channel and Speaker 2 channel will be automatically selected, allowing audio signals to pass through normally. When powered on again, the unit will automatically switch back to the amplifier and speaker channels that were set before shutdown.
7. Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior of the unit. Do not use liquid cleaners or solvents.
- Storage: Store the device in a cool, dry place away from direct sunlight and extreme temperatures.
- Connections: Periodically check all audio connections to ensure they are secure and free from corrosion.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No power to the unit. | USB power cable not connected or faulty; power adapter not working. | Ensure the USB cable is securely connected to the VU3 and a working 5V/1A+ power adapter. Try a different USB cable or power adapter. |
| No audio output. | Incorrect amplifier/speaker selection; loose audio connections; faulty cables. | Verify that the correct amplifier (A or B) and speaker (1 or 2) are selected. Check all banana plug connections for tightness and correct polarity. Test with different audio cables. |
| VU meters not moving or moving erratically. | No audio signal; swing-range knob set too low; faulty VU meter. | Ensure an audio signal is present. Adjust the 'SWING-RANGE' knob towards 'MAX'. If the issue persists, contact support. |
| Remote control not working. | No battery; incorrect battery type; battery drained; IR path blocked. | Insert a CR2025 3V battery. Replace the battery if it's old. Ensure there are no obstructions between the remote and the VU3's IR receiver. |
| Unit damaged after connecting to an amplifier. | Amplifier output power exceeded 300W per channel. | The VU3 is designed for a maximum of 300W per channel. Connecting higher power amplifiers can cause damage. This is not covered under warranty. |
9. Specifications
| Feature | Specification |
|---|---|
| Audio Input/Output | 2 groups of banana female jacks |
| Working Mode | 2-IN-1-OUT / 1-IN-2-OUT |
| Supported Amplifier Types | BTL / Class A / Class AB / Class B / Class D digital amp / Tube amp, etc. |
| Max. Through Power (each channel) | 300W (actual) |
| Backlight Brightness Adjustment | 4 levels (can be turned off) |
| Amplifier No-Load Protection | Supported |
| Remote Control Function | Supported |
| Settings Saved After Shutdown | Supported |
| Working Voltage | DC 5V (above 1A) |
| Power Interface | Type-C |
| Remote Control Battery Model | CR2025 3V (may not be included) |
| Diameter of VU Meter | 60*35mm |
| Dimensions (W*D*H) | 178*118*68mm / 7.01*4.65*2.68in |
| Net Weight | 980g / 2.16lb |
| Package Weight | 1.2kg / 2.65lb |
10. User Tips
- Remote Battery: The remote control typically requires a CR2025 3V battery, which might not be included for safer and faster shipping. Please prepare one yourself.
- Power Handling: To prevent damage, avoid connecting the VU3 to amplifiers with an actual output power exceeding 300W per channel.
- Power-Off Memory: When the unit is powered off, it defaults to Amplifier B and Speaker 2 channels, allowing audio passthrough. Upon powering on again, it will recall the last selected channels.
11. Warranty & Support
For warranty information, technical support, or service inquiries, please refer to the seller's policies or contact the manufacturer directly. Keep your purchase receipt as proof of purchase.
